(1) Field of Invention
The present invention relates to a method for transmitting information to a subscriber in a telephone system in connection with call establishment. The invention further relates to a cellular radio system comprising mobile stations and means for establishing a call to the mobile stations over a radio path. The invention further relates to a mobile station comprising means for establishing a telecommunication connection to the other parts of the system by radio-frequency signals.
The present invention relates particularly to transmitting information between subscribers in cellular radio systems although the invention can also be applied to a fixed telephone network. In the following, however, the invention will be described by way of example with reference to cellular radio systems.
(2) Description of Related Art
In the known cellular radio systems, the possessor of a mobile station can, for example at a meeting, set his or her mobile station in a silent mode in which its ringing tone is muted. A caller, i.e. an A subscriber, placing a call to a mobile station which is in the silent mode is not, however, provided with any information about this until the possessor of the mobile station, i.e. a B subscriber, answers the call terminating at him or her. In such a situation, since it may take longer than usual before the call is answered, the A subscriber may run out of patience and stop the call attempt before the B subscriber has the time to answer.
Cellular radio systems are previously known in which an A-subscriber-identifier is transmitted to the B subscriber in connection with a terminating call. The B subscriber can identify the connection from which the call is being placed to him or her, i.e. in practice the number of the caller, on the basis of the A-subscriber-identifier. A disadvantage of these known solutions is, however, that the identification of the A subscriber succeeds only if the A-subscriber-identifier transmitted to the B subscriber is previously known to him or her, and if the caller is the person who normally uses the particular phone. In other words, since the identification of the A subscriber is specifically based on the identification of the connection, the identification does not succeed if somebody else uses that phone.